Save your money and install a Detroit Quiet Locker. I put one on my Metro (had Rockwells) and it was awesome. It made no noise and I had zero issues turning.

When I was active in mudding, I can't tell you how many people I've seen with welded front diffs that had to make 35 point turnes to get around a corner. Yes, you will see a vast improvement in traction going through the mud but it's more of a pain in the ass than it's worth.